basic connection pooling question

Hey, I'm new to JDBC and I am looking at a connection pooling mechanism. OnCore Servlets I found a basic implementation. But in ConnectionPool.getConnection() I see

that Connection.isClosed() is used (see ($$$$))with a comment that it returns true if the connection has timed out. I assume this is wrong (based on the java documentation), but how should I replace this test if I want that my method returns an open connection?